Operation
The unit will continue cycling between Float and Silent for as long as the AC source is present. However, if excess DC power is available and the battery voltage rises above the Sell Voltage set point, the unit can resume Offset activity as described on page 21.
The unit can only enter Offset when none of the timers are active. If any of the timers have accumulated time while in Silent, the unit will enter the highest stage with accumulated time and proceed from that point.
Voltage | Absorption |
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| Absorption |
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Absorption Set Point |
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Float Set Point |
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Sell Set Point |
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| Float |
Refloat Set Point | Offset |
| Offset |
| Timer |
Rebulk Point |
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| Silent | Float |
| AC Loss |
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| Bulk |
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No | Bulk |
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Charge |
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| Time |
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| Figure 5 Repeated Charging Cycles |
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New Charging Cycle
If the AC source is lost or disconnected, the unit will return to inverting mode if enabled. The battery voltage will begin to decrease due to loads or natural loss. When the AC source is restored, the inverter will return to the charging cycle. If the batteries drop below the Rebulk voltage (see below), the inverter will restart the cycle, beginning at Bulk stage. If the batteries do not drop below Rebulk, the charger will not enter the Bulk stage and will return to its previous stage.
New Absorption Stage
When entering the second stage, Absorption, the charger will not necessarily run through its full duration. The timer will count down whatever time remains from the previous cycle, or whatever time it has accumulated since then.
Absorption Timer
The Absorption timer does not reset to its maximum like the Float timer does. Instead, the timer counts upward (gaining time) whenever the battery voltage drops below the Rebulk point. This means that the Absorption period may not always be the same, depending on how much time it has acquired.
The Rebulk voltage is 48.8 Vdc. This is a fixed setting and cannot be changed. For as long as the inverter remains below this voltage, the Absorption timer will gain an equal amount of time. This dictates the duration of the Absorption stage. Note that in Figure 5, the duration of time spent below the Rebulk voltage is the same as the subsequent Absorption period (as shown by the small arrows).
If the battery voltage drops below 48.0 Vdc, the timer increments (counts upward) at double the normal rate. For example, if the batteries spent 8 minutes below this voltage, 16 minutes would be added to the Absorption timer. Similarly, if the battery voltage drops below 47.2 Vdc, the timer increments at quadruple the normal rate.
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